Elegant Web3js functionality in Swift. Native ABI parsing and smart contract interactions.

What's New



What's Changed

New Contributors

  • @zmgl made their first contribution in #849

Full Changelog: 3.2.0...3.2.1


web3swift is an iOS toolbelt for interaction with the Ethereum network.

Social media

Join our discord or Telegram if you need support or want to contribute to web3swift development!

matter-github-swift Web3swift CI Swift Platform CocoaPods Compatible License Stackoverflow

Core features

  • ⚡ Swift implementation of web3.js functionality
  • 💭 Interaction with remote node via JSON RPC
  • 🔐 Local keystore management (geth compatible)
  • 🤖 Smart-contract ABI parsing
  • 🔓ABI decoding (V2 is supported with return of structures from public functions. Part of 0.4.22 Solidity compiler)
  • 🕸Ethereum Name Service (ENS) support - a secure & decentralised way to address resources both on and off the blockchain using simple, human-readable names
  • 🔄 Smart contracts interactions (read/write)
  • Infura support
  • Parsing TxPool content into native values (ethereum addresses and transactions) - easy to get pending transactions
  • 🖇 Event loops functionality
  • 🕵️‍♂️ Possibility to add or remove "middleware" that intercepts, modifies and even cancel transaction workflow on stages "before assembly", "after assembly" and "before submission"
  • Literally following the standards (BIP, EIP, etc):
    • BIP32 (HD Wallets), BIP39 (Seed phrases), BIP44 (Key generation prefixes)
  • EIP-20 (Standard interface for tokens - ERC-20), EIP-67 (Standard URI scheme), EIP-155 (Replay attacks protection), EIP-2718 (Typed Transaction Envelope), EIP-1559 (Gas Fee market change)
    • And many others (For details about this EIP's look at Documentation page): EIP-165, EIP-681, EIP-721, EIP-777, EIP-820, EIP-888, EIP-1155, EIP-1376, EIP-1400, EIP-1410, EIP-1594, EIP-1633, EIP-1643, EIP-1644, EIP-4361 (SIWE), ST-20
  • RLP encoding
  • Base58 encoding scheme
  • Formatting to and from Ethereum Units
  • Comprehensive Unit and Integration Test Coverage


Swift Package (Recommended)

The Swift Package Manager is a tool for automating the distribution of Swift code that is well integrated with Swift build system.

Once you have your Swift package set up, adding web3swift as a dependency is as easy as adding it to the dependencies value of your Package.swift.

dependencies: [
    .package(url: "https://github.com/web3swift-team/web3swift.git", .upToNextMajor(from: "3.0.0"))

Or if your project is not a package follow these guidelines on how to add a Swift Package to your Xcode project.

Example usage

In the imports section:

import web3swift
import Web3Core


CocoaPods is a dependency manager for Cocoa projects. You can install it with the following command:

$ sudo gem install cocoapods

To integrate web3swift into your Xcode project using CocoaPods, specify it in your Podfile:

source 'https://github.com/CocoaPods/Specs.git'
platform :ios, '13.0'

target '<Your Target Name>' do
    pod 'web3swift'

Then, run the following command:

$ pod install

WARNING: CocoaPods is a powerful tool for managing dependencies in iOS development, but it also has some limitations that preventing us of providing first class support there. We highly recommend using SPM first as using CocoaPods will delay new updates and bug fixes being delivered to you.

Send Ether

let transaction: CodableTransaction = .emptyTransaction
transaction.from = from ?? transaction.sender // `sender` one is if you have private key of your wallet address, so public key e.g. your wallet address could be interpreted
transaction.value = value
transaction.gasLimitPolicy = .manual(78423)
transaction.gasPricePolicy = .manual(20000000000)

Contract read method

let contract = web3.contract(Web3.Utils.erc20ABI, at: receipt.contractAddress!)!
let readOp = contract.createReadOperation("name")!
readOp.transaction.from = EthereumAddress("0xe22b8979739D724343bd002F9f432F5990879901")
let response = try await readTX.callContractMethod()

Write Transaction and call smart contract method

let abiString = "[]" // some ABI string
let bytecode = Data.fromHex("") // some ABI bite sequence
let contract = web3.contract(abiString, at: nil, abiVersion: 2)!
let parameters: [Any] = [...]
let deployOp = contract.prepareDeploy(bytecode: bytecode, constructor: contract.contract.constructor, parameters: parameters)!
deployOp.transaction.from = "" // your address
deployOp.transaction.gasLimitPolicy = .manual(3000000)
let result = try await deployTx.writeToChain(password: "web3swift")

Sending network request to a node

func feeHistory(blockCount: UInt, block: BlockNumber, percentiles:[Double]) async throws -> Web3.Oracle.FeeHistory {
    let requestCall: APIRequest = .feeHistory(blockCount, block, percentiles)
    let response: APIResponse<Web3.Oracle.FeeHistory> = try await APIRequest.sendRequest(with: web3.provider, for: requestCall) /// explicitly declaring `Result` type is **required**.
    return response.result

Build from source


git clone https://github.com/web3swift-team/web3swift.git
cd web3swift
swift build


  • iOS 13.0 / macOS 10.15
  • Xcode 12.5
  • Swift 5.5


Documentation is under construction👷🏻👷🏼‍♀️. We’re trying our best to comment all public API as detailed as we can, but the end it still far to come. But in one of the nearest minor updates we’ll bring DocC support of already done amount of docs. And your PR in such are more than welcome.

Projects that are using web3swift

Please take a look at Our customers wiki page.


Join our discord and Telegram if you need support or want to contribute to web3swift development!


To do local development and run the local tests, we recommend to use ganache which is also used by CI when running github actions.

// To install
$ npm install ganache --global

// To run
$ ganache

This will create a local blockchain and also some test accounts that are used throughout our tests. Make sure that ganache is running on its default port 8546. To change the port in test cases locate LocalTestCase.swift and modify the static url variable.

Before you commit

We are using pre-commit to run validations locally before a commit is created. Please, install pre-commit and run pre-commit install from project's root directory. After that before every commit git hook will run and execute codespell, swiftlint and other checks.


Want to improve? It's awesome: Then good news for you: We are ready to pay for your contribution via @gitcoin bot!


  1. You are more than welcome to participate and get bounty by contributing! Your contribution will be paid via @gitcoin Grant program.
  2. Find or create an issue
  3. You can find open bounties in Gitcoin Bounties list
  4. Commita fix or a new feature in branch, push your changes
  5. Submit a pull request to develop branch
    1. Please, provide detailed description to it to help us proceed it faster.

@skywinder are charged with open-sourсe and do not require money for using web3swift library. We want to continue to do everything we can to move the needle forward.


Security Disclosure

If you believe you have identified a security vulnerability with web3swift, you should report it as soon as possible via email to web3swift@oxor.io. Please do not post it to a public issue tracker.


web3swift is available under the Apache License 2.0 license. See the LICENSE for details.


  • Swift Tools 5.5.0
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Last updated: Fri May 24 2024 10:08:23 GMT-0900 (Hawaii-Aleutian Daylight Time)